If it would be anything like diplomacy in Vanguard, I would be all over it.

Would be sorta interesting, but I'd be curious to see how they'd make it work in the game. You can't just stick a card game in there and go, "We heard you like games, so we put a game in your game so you can get your game on while you game." Games have tried that before and it rarely feels "good" because it's so freaking random.

Yo dawg, how d'you know I like games in mah games?

I've always wanted to get into some kind of ONLINE TCG, recently tried playing Pokémon TCG Online but it's in beta and still very buggy.

I'm perfectly fine with any timewasters they add into GW2, as long as it doesn't take away too much of their time developing PvE/PvP content.
I mean, if they add one I don't like, no one's forcing me to play it. Besides the voice in my head telling me that I have to try everything GW2 offers. We'll ignore him for now.